The basics of diabetes treatment are said to be "diet" and "exercise." However, many people are worried, saying, "I'm careful about what I eat, but I don't know what kind of exercise I should do, or how much."
Exercise does more than just burn calories. It is a treatment that can be expected to have both an immediate effect of lowering blood sugar levels and a sustained effect of changing the body's constitution to be more responsive to insulin
In this article, we will explain in detail the mechanism behind why exercise is effective against diabetes, the combination of two types of exercise that is effective in improving blood sugar levels, and precautions to take to exercise safely.
table of contents
Why exercise helps control blood sugar
Exercise therapy is very important as one of the basic treatments for type 2 diabetes. For type 1 diabetes, there is no consensus on its direct effect on blood sugar control, but it is expected to have effects such as reducing risk factors for cardiovascular disease and improving quality of life (QOL)
Here we explain why exercise lowers blood sugar levels.
Short-term effects of exercise | Direct glucose consumption
The first is its immediate effect. When you exercise, your muscles directly take in and consume glucose from the blood as an energy source, lowering your blood sugar level. Exercising "after a meal" is particularly effective in suppressing blood sugar levels (blood sugar spikes) that tend to rise rapidly after eating.
Long-term effects of exercise | Improved insulin resistance
The second effect is that it changes the body itself. By continuing to exercise and building muscle or maintaining your current muscle mass, your basal metabolic rate increases. Even more importantly, it improves the "effectiveness of insulin" in the muscles (improving insulin sensitivity). This changes the body into one in which blood sugar levels are less likely to rise. Other reported effects include a reduction in visceral fat, which is a risk factor for cardiovascular disease, and improvements in cognitive dysfunction.
source:Diabetes Care Guidelines 2024 | Chapter 4 Exercise Therapy
[Practical Edition] Three exercises that are effective in improving blood sugar levels
There are three main types of exercise that are effective in improving diabetes. The basics are "aerobic exercise," which burns fat, and "resistance exercise (strength training)," which builds muscles. By combining these two, you can expect even greater results. Furthermore, in recent years, the effectiveness of "balance exercise," which helps prevent falls and improves cardiopulmonary function, has also been attracting attention.
aerobic exercise
Examples of exercise include walking, brisk walking, jogging, swimming, etc. These exercises consume carbohydrates and lipids as energy sources and improve cardiopulmonary function.
- Frequency and duration: It is recommended to exercise for a total of at least 150 minutes per week. The key is to exercise at least three days per week, and not to go two days in a row without exercising.
- Intensity: A good guideline is to work at a level that feels "easy" to "slightly hard" (RPE 11-12). In terms of pulse rate, it's best to work at about 50-60% of your maximum heart rate (220 - estimated based on your age).
Elderly people, people with autonomic nervous system disorders, and people taking antihypertensive medications (beta-blockers) may find it difficult to increase their pulse rate, so care should be taken not to determine intensity based on pulse rate alone.
Resistance exercise (strength training)
Resistance exercises such as squats, dumbbell exercises, and push-ups increase muscle mass and improve insulin resistance, helping to control blood sugar.
- Frequency: Recommended 2-3 times per week on non-consecutive days.
- Contents: Do at least one set of five or more exercises that involve major muscle groups such as the chest, back, and legs. Gradually increase the intensity and number of sets as you get used to it. Using heavier loads such as dumbbells or machines may produce better results.
Resistance exercise is just as effective as aerobic exercise, making it an effective option for elderly people who have difficulty with aerobic exercise due to weak legs and hips. In this case, it can also be expected to be effective in preventing muscle loss (sarcopenia).
balance exercise
Recently, the effects of balance exercises such as yoga and tai chi have been attracting attention. Yoga has been reported to not only improve fasting blood glucose levels and HbA1c, but also muscle strength and cardiopulmonary function. Tai chi is also said to improve blood glucose levels and balance ability. Research is still limited, so this is an area that requires further investigation, but it is an exercise style that is expected to be actively introduced.
It has been shown that combining resistance exercise with balance exercises may reduce the risk of falls in older adults.
source:Diabetes Care Guidelines 2024 | Chapter 4 Exercise Therapy
Precautions for safe exercise therapy
Exercise is like medicine; it requires appropriate dosage and care. If you have any medical conditions, do not start exercise on your own, but always consult with your doctor.
Why you need to consult your doctor
If you exercise excessively while you have complications, there is a risk that your condition may worsen.
- Diabetic retinopathy: If your condition has progressed (pre-proliferative retinopathy or worse), you may be restricted from doing strenuous aerobic exercise or jumping, as this can lead to retinal hemorrhage and retinal detachment. Be sure to get checked by an ophthalmologist.
- Diabetic nephropathy: If you have microalbuminuria, exercise needs to be considered individually.
- Diabetic neuropathy: If you have reduced sensation in your feet, you may not notice blisters or injuries, putting you at risk of worsening your foot condition.
Depending on the medical condition, it may be prohibited.
If you need to consult your doctor
Light exercise at the level of everyday life is usually safe to start without consulting a doctor, but if you are in any of the following situations, you should undergo a medical check-up before starting any exercise.
- When you start exercising at a higher intensity than usual.
- If you have other lifestyle-related diseases or poor blood sugar control, and are therefore at high risk of cardiovascular disease.
- When someone who normally leads a sedentary lifestyle starts moderate to high intensity exercise.
Even if you are not one of the above, if you have any concerns, we recommend that you consult a doctor.
source:Diabetes Care Guidelines 2024 | Chapter 4 Exercise Therapy
source:2023 Revised Edition Clinical Practice Guidelines for Primary Prevention of Coronary Artery Disease | Chapter 2: Assessment and Treatment of Risk Factors
summary
The best exercise therapy for diabetes is a combination of aerobic exercise to burn fat and resistance exercise to build muscle. Exercise has both the immediate effect of lowering blood sugar levels after meals and the long-term effect of creating a body that is less likely to gain weight and has a lower blood sugar level.
It's fine to start with something small like "walking 10 minutes more than you do now" or "doing 10 squats." The shortcut to good health is to continue exercising comfortably, safely, and for a long time.
Supervised by: Dr. Yuzo Terakawa (neurosurgery specialist)